Slab or block for pavements or floors



(No Model.)

0. BROWN.

SLAB 0R BLOCK FOR PAVEMENTS 0R FLOORS.

Patented Feb. 28,1882.

UNITED STATES PATENT OFFICE.

CALVIN BROWN, OF VALLEJO, CALIFORNIA.

SLAB OR BLOCK FOR PAVEMENTS OR FLOORS.

SPECIFICATION forming part of Letters Patent No. 254,269, dated February 28, 1882.

Application filed January 23, 1882.

To all whom it may concern Be it known that I, CALVIN BRowN, of Vallejo, in the county of Solano and State of California, have invented a new and useful Improvement in the Manufacture of Slabs or Blocks for Pavements and Floors, of which the following is a specification.

The invention relates to the form of the slabs of which pavements and floors may be composed.

Heretofore such slabs have been made of equal thickness throughout, the bottom and top surfaces being parallel planes, and whether they were made separately and afterward laid in place, or were molded in the place they were permanently to occupy, the foundations or beds upon which they rested were forced to be accurately leveled or dressed to receive them, and the slabs themselves, in order to be properly fitted to such foundations, were compelled to be of the same thickness in their whole extent, thus involving a greater quantity of materials in their manufacture than is necessary for their requisite strength, besides extra labor in leveling and preparing their foundations and in their setting.

The object of my improvement is to reduce the quantity of material in the manufacture of pavements and floors, to give the slabs composing them grater strength, and to fit them so as to be laid with a less amount of labor than heretofore necessary.

The invention consists in forming a concavity in the bottom ofthe slab, leaving its borders of a suitable width and continuous thickness to act as abutments to the arch thus constructed. Itis evident that this concavity may be cylindrical, spherical, ellipsoidal, 850., according to the outline or figure of the slab, and that these concavities may be multiplied to any required number, leaving between their perimeters such widths and thickness of material as may operate as braces or piers to the arches, thus lessening the weight and increasing the strength of large patterns.

(No model.)

In the accompanying drawings, in which similar letters of reference indicate like parts, Figure 1 is a perspective of a hexagon pavement-slab illustrating my invention, conceived to be standing on edge for the clearer exhibition of the concave bottom or bed C. Fig. 2 is a plan of the slab, showing the bottom uppermost. Fig. 3 is a section of the same, taken .on the line a 1), showing the concavity C. Fig.

4 is a perspective of a piece of pavement laid in place, showing the half-slabs D D used for completin g the area of the work.

The manufacture of the aforesaid pavementslabs of any desired outline may be effected either by means of molds, leaving them to set and harden before being permanently laid in place, or by being molded in the places they are to occupy in use, in the latter case the foundation-beds upon which they are to remain being shaped so as to give the required form of the concavity.

In the setting of the slabs previously formed in molds, and after they are hardened so as tobe safely handled, it is unnecessary in the preparation of their beds, whether of plastic mortar, sand, gravel, &c., to accurately level the whole surface, the only precaution needed being to have material enough under the borders of the slabs, so that in settling or ramming them intoplace any surplus material in ay rise into the concavity, and thus leave them solidly sustained on their strongest bearing parts--namely, their sides or borders.

What I claim is A paving-block having its outer edge of a continuous thickness and the lower-surface hollowed out, substantially as shown, whereby the sand or other material in which the block is laid may crowd up beneath the block, substantially as set forth.

In witness whereof I hereunto set my hand.

CALVIN BROWN.

Witnesses: I

GEO. H. STRONG, S. H. NoURsE. 

